Track-type machines are in widespread use in construction, mining, forestry, and other similar industries. The undercarriage of such track-type machines utilizes track assemblies, rather than wheels, to provide ground-engaging propulsion. Such track assemblies may be preferred in environments, such as the environments identified above, where creating sufficient traction is problematic. Specifically, rather than rolling across a work surface on wheels, track-type machines utilize one or more track assemblies that include an endless loop of coupled track links defining outer surfaces, which support ground-engaging track shoes, and inner surfaces that travel about one or more rotatable track-engaging elements, such as, for example, drive sprockets, idlers, tensioners, and rollers.
Track seals are disposed between the components of a track chain of a tracked undercarriage in order to seal the track chain against dirt, mud, and debris while retaining lubricants in the track chain. The failure of a seal within a track chain can accelerate wear and cause early failure of a portion of the track chain.
A common type of seal used in track chains is referred to as a “can” seal. A can seal often includes a “lip” supported by a can and a load ring engaging the can. The surface defining a seal cavity can interact with the load ring to apply a force to the can and the lip. The lip engages a sealing surface of an adjacent component. Together, the can seal, the surface defining the seal cavity, and the sealing surface of the adjacent component provide a sealed interface to retain lubricant within the assembly and protect against dirt, mud, abrasive materials, debris and other contaminants. Examples of such can seals are shown and described in U.S. Patent Application Publication No. US 2007/10267821; U.S. Pat. Nos. 5,794,940 and 4,094,516; and International Publication No. WO 2008/093160 A1.
One cause of failure of current can-type seals is known in the art as “heel under.” Heel under describes the situation where debris is ingested between an outer surface of the load ring and the seal cavity. The debris builds up and can cause the load ring to rotate or move out of position against the can resulting in the failure of the can seal and leakage of lubricant.
It will be appreciated that this background description has been created by the inventors to aid the reader, and is not to be taken as an indication that any of the indicated problems were themselves appreciated in the art. While the described principles can, in some respects and embodiments, alleviate the problems inherent in other systems, it will be appreciated that the scope of the protected innovation is defined by the attached claims, and not by the ability of any disclosed feature to solve any specific problem noted herein.